The title compound 5'-chloro-1H,1"H-[3,3':3',3"-terindol]-2'(1'H)-one is synthesized via one-pot multicomponent reaction (MCR) at room temperature using commercially available sulfamic acid as inexpensive and environmentally benign organo-catalyst. It crystallizes in the monoclinic space group P21/n with the unit-cell parameters: a = 15.3117(15), b = 10.9302(8), c = 16.591(2) Å, 90.00o β = 98.224(10) , γ = 90.00 and Z = 4. The crystal structure was solved by direct methods using single-crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R-value of 0.0735 for 2539 observed reflections. Both the DMSO solvent molecules take part in the inter- and intramolecular interactions that are responsible for the formation of hydrogen bonded network. Two C-H∙∙∙π inter-molecular hydrogen bonds are also present in the crystal structure.